Sprint 2: HostedPluginManager.h \u2014 full plugin hosting interface with param surface

Source/HostedPluginManager.h

@@ -1,13 +1,55 @@
 #pragma once
 
-// Phase 2 stub — will be implemented in Sprint 2
-// Manages loading/unloading of a hosted VST3/AU plugin inside PluginBridge
+#include <juce_audio_processors/juce_audio_processors.h>
+#include <vector>
+#include <map>
 
 class HostedPluginManager
 {
 public:
-    HostedPluginManager() = default;
-    ~HostedPluginManager() = default;
+    HostedPluginManager();
+    ~HostedPluginManager();
 
-    bool isLoaded() const { return false; }
+    // Plugin lifecycle
+    void loadPlugin(const juce::File& pluginFile, double sampleRate, int blockSize);
+    void unloadPlugin();
+    bool isLoaded() const;
+    juce::String getPluginName() const;
+
+    // Audio processing — called from audio thread
+    void prepareToPlay(double sampleRate, int blockSize);
+    void processBlock(juce::AudioBuffer<float>& buffer, juce::MidiBuffer& midi);
+    void releaseResources();
+
+    // Parameter surface — called from HTTP thread (thread-safe)
+    struct ParamInfo {
+        int index;
+        juce::String id;
+        juce::String name;
+        float value;        // 0.0–1.0 normalized
+        juce::String displayText;
+        bool automatable;
+    };
+
+    std::vector<ParamInfo> searchParams(const juce::String& keyword) const;
+    std::vector<std::pair<int, float>> getParams(const std::vector<int>& indices) const;
+    bool setParams(const std::map<int, float>& values);
+    int getParameterCount() const;
+
+    // Thread safety
+    juce::CriticalSection& getPluginLock() { return pluginLock; }
+
+    // File path of currently loaded plugin (for state save/restore)
+    juce::String getLoadedPluginPath() const;
+
+private:
+    juce::AudioPluginFormatManager formatManager;
+    std::unique_ptr<juce::AudioPluginInstance> hostedPlugin;
+    juce::CriticalSection pluginLock;
+
+    double currentSampleRate = 44100.0;
+    int currentBlockSize = 512;
+    juce::String loadedPluginPath;
+
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(HostedPluginManager)
 };